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    Subject[PATCH 3.16 202/305] usb: core: Fix hub port connection events lost
    3.16.63-rc1 review patch.  If anyone has any objections, please let me know.

    ------------------

    From: Dennis Wassenberg <dennis.wassenberg@secunet.com>

    commit 22454b79e6de05fa61a2a72d00d2eed798abbb75 upstream.

    This will clear the USB_PORT_FEAT_C_CONNECTION bit in case of a hub port reset
    only if a device is was attached to the hub port before resetting the hub port.

    Using a Lenovo T480s attached to the ultra dock it was not possible to detect
    some usb-c devices at the dock usb-c ports because the hub_port_reset code
    will clear the USB_PORT_FEAT_C_CONNECTION bit after the actual hub port reset.
    Using this device combo the USB_PORT_FEAT_C_CONNECTION bit was set between the
    actual hub port reset and the clear of the USB_PORT_FEAT_C_CONNECTION bit.
    This ends up with clearing the USB_PORT_FEAT_C_CONNECTION bit after the
    new device was attached such that it was not detected.

    This patch will not clear the USB_PORT_FEAT_C_CONNECTION bit if there is
    currently no device attached to the port before the hub port reset.
    This will avoid clearing the connection bit for new attached devices.

    Signed-off-by: Dennis Wassenberg <dennis.wassenberg@secunet.com>
    Acked-by: Mathias Nyman <mathias.nyman@linux.intel.com>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
    Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
    ---
    drivers/usb/core/hub.c | 4 +++-
    1 file changed, 3 insertions(+), 1 deletion(-)

    --- a/drivers/usb/core/hub.c
    +++ b/drivers/usb/core/hub.c
    @@ -2725,7 +2725,9 @@ static int hub_port_reset(struct usb_hub
    USB_PORT_FEAT_C_BH_PORT_RESET);
    usb_clear_port_feature(hub->hdev, port1,
    USB_PORT_FEAT_C_PORT_LINK_STATE);
    - usb_clear_port_feature(hub->hdev, port1,
    +
    + if (udev)
    + usb_clear_port_feature(hub->hdev, port1,
    USB_PORT_FEAT_C_CONNECTION);

    /*
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